Many microelectromechanical systems (MEMSs) have enabled coated microcantilevers and microbeams to be used as sensors.
One example of a MEMs based sensor is described in T. Thundat, E. A. Wachter, S. L. Sharp, and R. Warmack, Appl. Phys. Lett. 66, 1695 (1995). Another example is described in T. Thundat et al., “Micromechanical radiation dosimeter”, Appl. Phys. Lett., Vol. 66, Issue 12, March 1995, pages 1563-1565. E. A. Wacheter et al. describe measurement of resonance frequency and static bending of a microcantilever in “Micromechanical sensors for chemical and physical measurements”, Rev. Sci. Instrum., Vol. 66, Issue 6, June 1995, pages 3662-3667.
Another example is described in E. A. Wachter et al., “Remote Optical Detection using Microcantilevers”, Rev. Sci Instrum., Vol. 67, Issue 10, pages 3434-3439, October 1996. Another example is described in R. T. Howe and R. S. Muller, IEEE Trans. Electron Devices 33, 499, (1986). L. A. Pinnaduwage, V. Boiadjiev, J. E. Hawk, and T. Thundat, Appl. Phys. Lett. 83, 1471 (2003) describes chemical vapor detection at a level of 30 parts per trillion. Fritz, M. K. Baller, H. P. Lang, H. Rothuizen, P. Vettiger, E. Meyer, H. J. Güntherodt, C. Gerber, and J. K. Gimzewski, Science 288, 316 (2000) describes detection of single DNA base pairs. In another example, N. V. Lavrik and P. G. Datskos, Appl. Phys. Lett. 82, 2697 (2003) describes detection at the level of 6 femtograms using photothermal actuation and interferometric readout of microcantilever resonators.
Optical interferometry is used to detect differential and absolute deflections of two adjacent cantilevers in C. A. Savran, “Fabrication and Characterization of a Micromechanical Sensor for Differential Detection of Nanoscale Motions”, J. Micromechanical Systems, Vol. 11, No. 6, December 2002, pages 703-708.
A scanning laser doppler vibrometer suitable for microcomponents is described in B. K. A. Ngoi et al., “Laser scanning heterodyne-interferometer for micro-components”, Optics Communications, Vol. 173, pages 291-301, January 2000.
J. F. Vignola et al. describe MEMS oscillators in “Characterization of silicon micro-oscillators by scanning laser vibrometry”, Review of Scientific Instruments, Vol. 73, No. 10, October 2002, pages 3584-3588.
Attention is also drawn to G. Meyer et al., “Novel optical approach to atomic force microscopy”, Appl. Phys Lett., Vol. 53, No. 12, September 1988, pages 1045-1047 for discussion of a position sensitive detector for measuring displacement of a cantilever beam.
C. Cornilla et al. describe an integrated capacitive chemical sensor in “Capacitive sensors in CMOS technology with polymer coating”, Sensors and Actuators B, Vol. 24-25, pages 357-361 (1995). Microcantilever biosensors are described in K. M. Hansen et al., “Microcantilever biosensors”, Methods, Vol. 37, Issue 1, pages 57-64, 2005.
A chemical sensor using microcantilevers is described in J. D. Adams et al., “Nanowatt chemical vapor detection with a self sensing, piezoelectric microcantilever array. Another chemical sensor using microcantilevers is described in commonly assigned U.S. patent application Ser. No. 11/136,763, entitled “Microelectro-mechanical chemical sensor”, filed May 25, 2005, with inventors Robert Andrew McGill, Gary K Fedder, and Ioana Voiculescu.
Optical measurement of noise from MEMs structures is described in T. H. Stievater et al., “Measurement of thermal-mechanical noise in microelectromechanical systems”, Applied Physics Letters, Vol. 81, No. 10, pages 1779-1781, Sep. 2002. Microcavity interferometric measurement of an electrostatically actuated microcantilever is described in T. H. Stievater, W. S. Rabinovich, H. S. Newman, J. L. Ebel, R. Mahon, D. J. McGee, and P. G. Goetz, J. Microelectromech. Syst. 12, 109 (2003).